Thermostatic circuit-closer.



No. 834,952. PATENTED Nov. 6,1906.

0. L. WALKER.

THERMOSTATIG CIRGUIT CLOSER.

. APPLIGATION IILEDMAR. 25, 1904.

THE NORRIS pzrzns co. wnsnmsrcu n c CHARLES LESLIE WALKER, OF HARRO W, ENGLAND.

THERMOSTATIC CIRCUIT-CLOSER.

Specification of Letters Patent.

Patented NOV. 6, 1906.

Application fil d March 25.1904. Serial No. 199,907-

To all whom it may concern.-

Be it known that I, CHARLES LESLIE IVALKER, civil engineer, a subject of the King of Great Britain, residing at The Hut, Mount Park Road, Harrow, in the county of Middlesex, England, have invented certain new and useful Improvements in Thermostatic Circuit-Closers, of which the following is a specification.

This invent-ion relates to thermostatic cir cuit-closers connected with firealarms, in whichthe action is caused by the unequal rate of expansion of the fluid contained in two vessels, one of which exposes a large surface in comparison to its mass to the surrounding air and whose contents are more quickly effected by heat than the contents of the other vessel, this being effected by increasing the thickness of the other vessel. The two vessels are connected together by a U-shaped tube in which there is a cavity. A thermometric fluid, such as mercury, is contained in the U-shaped tube and in the cavity, and this fluid may be made to cooperate with contacts to close an electric circuit.

The device may be caused to give a signal, open a sprinkler, or perform other suitable actions either by closing an electric circuit, as above specified, or by opening a closed circuit.

The accompanying drawing shows a vertical central section through a thermostatic circuit-closer made in accordance with this invention.

In the drawing, a and 1) illustrate tubes containing a suitable fluid, the tube 1) being thickened at c, and both tubes are connected by a U-shaped tube 01, the bore of which is of smaller diameter than the bore of the tubes or vessels at b. The tube d contains mercury or other thermometric electroconductive liquid. In the tube d is a cavity 6, and f is a wire in contact with the mercury in the cavity. 9 is another wire which under normal circumstances is not in contact with the mercury. When there is a sudden rise of temperature, the air or gas in the tube a expands more quickly than that in the tube 1), forcing the mercury to make contact with the wire g, and thus close the electric circuit.

In case of a smoldering fire the large body of mercury in the cavity e expands and makes contact with the wire g.

I have illustrated the simplest and best way known to me of carrying out my invention; but, as before stated, the device may be arranged to break a circuit instead of closing it and may be otherwise arranged to operate in case of a smoldering fire.

I claim as my invention- 1. In a thermostatic circuit-closer, the

combination of two vessels containing thermometric fluid, one of which exposes a large surface in comparison to its mass to the surrounding air and whose contents are more quickly affected by heat than the contents of the other, a passage containing a liquid connecting the two vessels, electric contacts therein where the circuit is made or broken by the movement of the liquid when actuated by a sudden rise in temperature, and means connected with said vessels and passage for moving said fluid to open or close said circuit when the rise of temperature is slow as in the case of a smoldering fire.

2. The combination of a vessel containing thermometric fluid and which exposes a large surface in comparison to its mass to the surrounding air, another vessel constructed to protect its contents from heat, and both containing a thermometric fluid, a U-shaped tube having a bore of relatively small crosssection containing an electroconductive liquid and connecting the two other vessels and which is provided with a cavity of relatively large area containing a relatively large amount of the electroconductive liquid, and an electric circuit opened or closed by said fluid.

CHARLES LESLIE WALKER. Witnesses:

R. B. RANsEoRD, JOHN H. WHITEHEAD. 

